mcs/class/System.Web/System.Web/HttpContext.cs

   1 //
   2 // System.Web.HttpContext.cs
   3 //
   4 // Author:
   5 //      Miguel de Icaza (miguel@novell.com)
   6 //      Gonzalo Paniagua Javier (gonzalo@novell.com)
   7 //      Marek Habersack <mhabersack@novell.com>
   8 //
   9
  10 //
  11 // Copyright (C) 2005-2009 Novell, Inc (http://www.novell.com)
  12 //
  13 // Permission is hereby granted, free of charge, to any person obtaining
  14 // a copy of this software and associated documentation files (the
  15 // "Software"), to deal in the Software without restriction, including
  16 // without limitation the rights to use, copy, modify, merge, publish,
  17 // distribute, sublicense, and/or sell copies of the Software, and to
  18 // permit persons to whom the Software is furnished to do so, subject to
  19 // the following conditions:
  20 //
  21 // The above copyright notice and this permission notice shall be
  22 // included in all copies or substantial portions of the Software.
  23 //
  24 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  28 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  29 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  30 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  31 //
  32
  33 using System.Collections;
  34 using System.Configuration;
  35 using System.Globalization;
  36 using System.Runtime.Remoting.Messaging;
  37 using System.Security.Permissions;
  38 using System.Security.Principal;
  39 using System.Threading;
  40 using System.Web.Caching;
  41 using System.Web.Configuration;
  42 using System.Web.SessionState;
  43 using System.Web.UI;
  44 using System.Web.Util;
  45 using System.Reflection;
  46 using System.Collections.Generic;
  47 using System.IO;
  48 using System.Resources;
  49 using System.Web.Compilation;
  50 using System.Web.Profile;
  51 using CustomErrorMode = System.Web.Configuration.CustomErrorsMode;
  52
  53 namespace System.Web
  54 {
  55         // CAS - no InheritanceDemand here as the class is sealed
  56         [AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  57         public sealed partial class HttpContext : IServiceProvider
  58         {
  59                 internal HttpWorkerRequest WorkerRequest;
  60                 HttpApplication app_instance;
  61                 HttpRequest request;
  62                 HttpResponse response;
  63                 HttpSessionState session_state;
  64                 HttpServerUtility server;
  65                 TraceContext trace_context;
  66                 IHttpHandler handler;
  67                 string error_page;
  68                 bool skip_authorization = false;
  69                 IPrincipal user;
  70                 object errors;
  71                 Hashtable items;
  72                 object config_timeout;
  73                 int timeout_possible;
  74                 DateTime time_stamp = DateTime.UtcNow;
  75                 Timer timer;
  76                 Thread thread;
  77                 bool _isProcessingInclude;
  78
  79                 [ThreadStatic]
  80                 static ResourceProviderFactory provider_factory;
  81
  82                 [ThreadStatic]
  83                 static DefaultResourceProviderFactory default_provider_factory;
  84
  85                 [ThreadStatic]
  86                 static Dictionary <string, IResourceProvider> resource_providers;
  87
  88 #if TARGET_JVM
  89                 const string app_global_res_key = "HttpContext.app_global_res_key";
  90                 internal static Assembly AppGlobalResourcesAssembly {
  91                         get { return (Assembly) AppDomain.CurrentDomain.GetData (app_global_res_key); }
  92                         set { AppDomain.CurrentDomain.SetData (app_global_res_key, value); }
  93                 }
  94 #else
  95                 internal static Assembly AppGlobalResourcesAssembly;
  96 #endif
  97                 ProfileBase profile = null;
  98                 LinkedList<IHttpHandler> handlers;
  99
 100                 static DefaultResourceProviderFactory DefaultProviderFactory {
 101                         get {
 102                                 if (default_provider_factory == null)
 103                                         default_provider_factory = new DefaultResourceProviderFactory ();
 104                                 return default_provider_factory;
 105                         }
 106                 }
 107
 108                 public HttpContext (HttpWorkerRequest wr)
 109                 {
 110                         WorkerRequest = wr;
 111                         request = new HttpRequest (WorkerRequest, this);
 112                         response = new HttpResponse (WorkerRequest, this);
 113                 }
 114
 115                 public HttpContext (HttpRequest request, HttpResponse response)
 116                 {
 117                         this.request = request;
 118                         this.response = response;
 119
 120                 }
 121
 122                 internal bool IsProcessingInclude {
 123                         get { return _isProcessingInclude; }
 124                         set { _isProcessingInclude = value; }
 125                 }
 126
 127                 public Exception [] AllErrors {
 128                         get {
 129                                 if (errors == null)
 130                                         return null;
 131
 132                                 if (errors is Exception){
 133                                         Exception [] all = new Exception [1];
 134                                         all [0] = (Exception) errors;
 135                                         return all;
 136                                 }
 137                                 return (Exception []) (((ArrayList) errors).ToArray (typeof (Exception)));
 138                         }
 139                 }
 140
 141                 public HttpApplicationState Application {
 142                         get {
 143                                 return HttpApplicationFactory.ApplicationState;
 144                         }
 145                 }
 146
 147                 public HttpApplication ApplicationInstance {
 148                         get {
 149                                 return app_instance;
 150                         }
 151
 152                         set {
 153                                 app_instance = value;
 154                         }
 155
 156                 }
 157
 158                 public Cache Cache {
 159                         get {
 160                                 return HttpRuntime.Cache;
 161                         }
 162                 }
 163
 164                 internal Cache InternalCache {
 165                         get {
 166                                 return HttpRuntime.InternalCache;
 167                         }
 168                 }
 169
 170                 //
 171                 // The "Current" property is set just after we have constructed it with
 172                 // the 'HttpContext (HttpWorkerRequest)' constructor.
 173                 //
 174 #if !TARGET_JVM // No remoting CallContext support in Grasshopper
 175                 public static HttpContext Current {
 176                         get {
 177                                 return (HttpContext) CallContext.GetData ("c");
 178                         }
 179
 180                         set {
 181                                 CallContext.SetData ("c", value);
 182                         }
 183                 }
 184 #endif
 185
 186                 public Exception Error {
 187                         get {
 188                                 if (errors == null || (errors is Exception))
 189                                         return (Exception) errors;
 190                                 return (Exception) (((ArrayList) errors) [0]);
 191                         }
 192                 }
 193
 194                 public IHttpHandler Handler {
 195                         get {
 196                                 return handler;
 197                         }
 198
 199                         set {
 200                                 handler = value;
 201                         }
 202                 }
 203
 204                 public bool IsCustomErrorEnabled {
 205                         get {
 206                                 try {
 207                                         return IsCustomErrorEnabledUnsafe;
 208                                 }
 209                                 catch {
 210                                         return false;
 211                                 }
 212                         }
 213                 }
 214
 215                 internal bool IsCustomErrorEnabledUnsafe {
 216                         get {
 217                                 CustomErrorsSection cfg = (CustomErrorsSection) WebConfigurationManager.GetSection ("system.web/customErrors");
 218                                 if (cfg.Mode == CustomErrorMode.On)
 219                                         return true;
 220
 221                                 return (cfg.Mode == CustomErrorMode.RemoteOnly) && !Request.IsLocal;
 222                         }
 223                 }
 224 #if !TARGET_JVM
 225                 public bool IsDebuggingEnabled {
 226                         get { return HttpRuntime.IsDebuggingEnabled; }
 227                 }
 228 #endif
 229                 public IDictionary Items {
 230                         get {
 231                                 if (items == null)
 232                                         items = new Hashtable ();
 233                                 return items;
 234                         }
 235                 }
 236
 237                 public HttpRequest Request {
 238                         get {
 239                                 return request;
 240                         }
 241                 }
 242
 243                 public HttpResponse Response {
 244                         get {
 245                                 return response;
 246                         }
 247                 }
 248
 249                 public HttpServerUtility Server {
 250                         get {
 251                                 if (server == null)
 252                                         server = new HttpServerUtility (this);
 253                                 return server;
 254                         }
 255                 }
 256
 257                 public HttpSessionState Session {
 258                         get {
 259                                 return session_state;
 260                         }
 261                 }
 262
 263                 public bool SkipAuthorization {
 264                         get {
 265                                 return skip_authorization;
 266                         }
 267
 268                         [SecurityPermission (SecurityAction.Demand, ControlPrincipal = true)]
 269                         set {
 270                                 skip_authorization = value;
 271                         }
 272                 }
 273
 274                 public DateTime Timestamp {
 275                         get {
 276                                 return time_stamp.ToLocalTime ();
 277                         }
 278                 }
 279
 280                 public TraceContext Trace {
 281                         get {
 282                                 if (trace_context == null)
 283                                         trace_context = new TraceContext (this);
 284                                 return trace_context;
 285                         }
 286                 }
 287
 288                 public IPrincipal User {
 289                         get {
 290                                 return user;
 291                         }
 292
 293                         [SecurityPermission (SecurityAction.Demand, ControlPrincipal = true)]
 294                         set {
 295                                 user = value;
 296                         }
 297                 }
 298
 299                 internal bool MapRequestHandlerDone {
 300                         get;
 301                         set;
 302                 }
 303
 304                 // The two properties below are defined only when the IIS7 integrated mode is used.
 305                 // They are useless under Mono
 306                 public RequestNotification CurrentNotification {
 307                         get { throw new PlatformNotSupportedException ("This property is not supported on Mono.");  }
 308                 }
 309
 310                 public bool IsPostNotification {
 311                         get { throw new PlatformNotSupportedException ("This property is not supported on Mono."); }
 312                 }
 313
 314                 internal void PushHandler (IHttpHandler handler)
 315                 {
 316                         if (handler == null)
 317                                 return;
 318                         if (handlers == null)
 319                                 handlers = new LinkedList <IHttpHandler> ();
 320                         handlers.AddLast (handler);
 321                 }
 322
 323                 internal void PopHandler ()
 324                 {
 325                         if (handlers == null || handlers.Count == 0)
 326                                 return;
 327                         handlers.RemoveLast ();
 328                 }
 329
 330                 IHttpHandler GetCurrentHandler ()
 331                 {
 332                         if (handlers == null || handlers.Count == 0)
 333                                 return null;
 334
 335                         return handlers.Last.Value;
 336                 }
 337
 338                 IHttpHandler GetPreviousHandler ()
 339                 {
 340                         if (handlers == null || handlers.Count <= 1)
 341                                 return null;
 342                         LinkedListNode <IHttpHandler> previous = handlers.Last.Previous;
 343                         if (previous != null)
 344                                 return previous.Value;
 345                         return null;
 346                 }
 347
 348                 public IHttpHandler CurrentHandler {
 349                         get { return GetCurrentHandler (); }
 350                 }
 351
 352                 public IHttpHandler PreviousHandler {
 353                         get { return GetPreviousHandler (); }
 354                 }
 355
 356                 internal bool ProfileInitialized {
 357                         get { return profile != null; }
 358                 }
 359
 360                 public ProfileBase Profile {
 361                         get {
 362                                 if (profile == null) {
 363                                         if (Request.IsAuthenticated)
 364                                                 profile = ProfileBase.Create (User.Identity.Name);
 365                                         else
 366                                                 profile = ProfileBase.Create (Request.AnonymousID, false);
 367                                 }
 368                                 return profile;
 369                         }
 370
 371                         internal set {
 372                                 profile = value;
 373                         }
 374                 }
 375
 376                 public void AddError (Exception errorInfo)
 377                 {
 378                         if (errors == null){
 379                                 errors = errorInfo;
 380                                 return;
 381                         }
 382                         ArrayList l;
 383                         if (errors is Exception){
 384                                 l = new ArrayList ();
 385                                 l.Add (errors);
 386                                 errors = l;
 387                         } else
 388                                 l = (ArrayList) errors;
 389                         l.Add (errorInfo);
 390                 }
 391
 392                 internal void ClearError (Exception e)
 393                 {
 394                         if (errors == e)
 395                                 errors = null;
 396                 }
 397
 398                 internal bool HasError (Exception e)
 399                 {
 400                         if (errors == e)
 401                                 return true;
 402
 403                         return (errors is ArrayList) ?
 404                                 ((ArrayList) errors).Contains (e) : false;
 405                 }
 406
 407                 public void ClearError ()
 408                 {
 409                         errors = null;
 410                 }
 411
 412                 [Obsolete ("use WebConfigurationManager.GetWebApplicationSection")]
 413                 public static object GetAppConfig (string name)
 414                 {
 415                         object o = ConfigurationSettings.GetConfig (name);
 416
 417                         return o;
 418                 }
 419
 420                 [Obsolete ("see GetSection")]
 421                 public object GetConfig (string name)
 422                 {
 423                         return GetSection (name);
 424                 }
 425
 426                 public static object GetGlobalResourceObject (string classKey, string resourceKey)
 427                 {
 428                         return GetGlobalResourceObject (classKey, resourceKey, Thread.CurrentThread.CurrentUICulture);
 429                 }
 430
 431                 static bool EnsureProviderFactory ()
 432                 {
 433                         if (resource_providers == null)
 434                                 resource_providers = new Dictionary <string, IResourceProvider> ();
 435
 436                         if (provider_factory != null)
 437                                 return true;
 438
 439                         GlobalizationSection gs = WebConfigurationManager.GetSection ("system.web/globalization") as GlobalizationSection;
 440
 441                         if (gs == null)
 442                                 return false;
 443
 444                         String rsfTypeName = gs.ResourceProviderFactoryType;
 445                         bool usingDefault = false;
 446                         if (String.IsNullOrEmpty (rsfTypeName)) {
 447                                 usingDefault = true;
 448                                 rsfTypeName = typeof (DefaultResourceProviderFactory).AssemblyQualifiedName;
 449                         }
 450
 451                         Type rsfType = HttpApplication.LoadType (rsfTypeName, true);
 452                         ResourceProviderFactory rpf = Activator.CreateInstance (rsfType) as ResourceProviderFactory;
 453
 454                         if (rpf == null && usingDefault)
 455                                 return false;
 456
 457                         provider_factory = rpf;
 458                         if (usingDefault)
 459                                 default_provider_factory = rpf as DefaultResourceProviderFactory;
 460
 461                         return true;
 462                 }
 463
 464                 internal static IResourceProvider GetResourceProvider (string virtualPath, bool isLocal)
 465                 {
 466                         if (!EnsureProviderFactory ())
 467                                 return null;
 468
 469                         // TODO: check if it makes sense to cache the providers and, if yes, maybe
 470                         // we should expire the entries (or just store them in InternalCache?)
 471                         IResourceProvider rp = null;
 472                         if (!resource_providers.TryGetValue (virtualPath, out rp)) {
 473                                 if (isLocal) {
 474                                         HttpContext ctx = HttpContext.Current;
 475                                         HttpRequest req = ctx != null ? ctx.Request : null;
 476                                         rp = provider_factory.CreateLocalResourceProvider (virtualPath);
 477                                 } else
 478                                         rp = provider_factory.CreateGlobalResourceProvider (virtualPath);
 479
 480                                 if (rp == null) {
 481                                         if (isLocal) {
 482                                                 HttpContext ctx = HttpContext.Current;
 483                                                 HttpRequest req = ctx != null ? ctx.Request : null;
 484                                                 rp = DefaultProviderFactory.CreateLocalResourceProvider (virtualPath);
 485                                         } else
 486                                                 rp = DefaultProviderFactory.CreateGlobalResourceProvider (virtualPath);
 487
 488                                         if (rp == null)
 489                                                 return null;
 490                                 }
 491
 492                                 resource_providers.Add (virtualPath, rp);
 493                         }
 494
 495                         return rp;
 496                 }
 497
 498                 static object GetGlobalObjectFromFactory (string classKey, string resourceKey, CultureInfo culture)
 499                 {
 500                         // FIXME: Retention of data
 501                         IResourceProvider rp = GetResourceProvider (classKey, false);
 502                         if (rp == null)
 503                                 return null;
 504
 505                         return rp.GetObject (resourceKey, culture);
 506                 }
 507
 508                 public static object GetGlobalResourceObject (string classKey, string resourceKey, CultureInfo culture)
 509                 {
 510                         return GetGlobalObjectFromFactory ("Resources." + classKey, resourceKey, culture);
 511                 }
 512
 513                 public static object GetLocalResourceObject (string virtualPath, string resourceKey)
 514                 {
 515                         return GetLocalResourceObject (virtualPath, resourceKey, Thread.CurrentThread.CurrentUICulture);
 516                 }
 517
 518                 static object GetLocalObjectFromFactory (string virtualPath, string resourceKey, CultureInfo culture)
 519                 {
 520                         IResourceProvider rp = GetResourceProvider (virtualPath, true);
 521                         if (rp == null)
 522                                 return null;
 523
 524                         return rp.GetObject (resourceKey, culture);
 525                 }
 526
 527                 public static object GetLocalResourceObject (string virtualPath, string resourceKey, CultureInfo culture)
 528                 {
 529                         if (!VirtualPathUtility.IsAbsolute (virtualPath))
 530                                 throw new ArgumentException ("The specified virtualPath was not rooted.");
 531
 532                         return GetLocalObjectFromFactory (virtualPath, resourceKey, culture);
 533                 }
 534
 535                 public object GetSection (string name)
 536                 {
 537                         return WebConfigurationManager.GetSection (name);
 538                 }
 539
 540                 object IServiceProvider.GetService (Type service)
 541                 {
 542                         if (service == typeof (HttpWorkerRequest))
 543                                 return WorkerRequest;
 544
 545                         //
 546                         // We return everything out of properties in case
 547                         // they are dynamically computed in some form in the future.
 548                         //
 549                         if (service == typeof (HttpApplication))
 550                                 return ApplicationInstance;
 551
 552                         if (service == typeof (HttpRequest))
 553                                 return Request;
 554
 555                         if (service == typeof (HttpResponse))
 556                                 return Response;
 557
 558                         if (service == typeof (HttpSessionState))
 559                                 return Session;
 560
 561                         if (service == typeof (HttpApplicationState))
 562                                 return Application;
 563
 564                         if (service == typeof (IPrincipal))
 565                                 return User;
 566
 567                         if (service == typeof (Cache))
 568                                 return Cache;
 569
 570                         if (service == typeof (HttpContext))
 571                                 return Current;
 572
 573                         if (service == typeof (IHttpHandler))
 574                                 return Handler;
 575
 576                         if (service == typeof (HttpServerUtility))
 577                                 return Server;
 578
 579                         if (service == typeof (TraceContext))
 580                                 return Trace;
 581
 582                         return null;
 583                 }
 584
 585                 public void RemapHandler (IHttpHandler handler)
 586                 {
 587                         if (MapRequestHandlerDone)
 588                                 throw new InvalidOperationException ("The RemapHandler method was called after the MapRequestHandler event occurred.");
 589                         Handler = handler;
 590                 }
 591
 592                 public void RewritePath (string path)
 593                 {
 594                         RewritePath (path, true);
 595                 }
 596
 597                 public void RewritePath (string filePath, string pathInfo, string queryString)
 598                 {
 599                         RewritePath (filePath, pathInfo, queryString, false);
 600                 }
 601
 602                 public void RewritePath (string path, bool rebaseClientPath)
 603                 {
 604                         int qmark = path.IndexOf ('?');
 605                         if (qmark != -1)
 606                                 RewritePath (path.Substring (0, qmark), String.Empty, path.Substring (qmark + 1), rebaseClientPath);
 607                         else
 608                                 RewritePath (path, null, null, rebaseClientPath);
 609                 }
 610
 611                 public void RewritePath (string filePath, string pathInfo, string queryString, bool setClientFilePath)
 612                 {
 613                         if (filePath == null)
 614                                 throw new ArgumentNullException ("filePath");
 615                         if (!VirtualPathUtility.IsValidVirtualPath (filePath))
 616                                 throw new HttpException ("'" + HttpUtility.HtmlEncode (filePath) + "' is not a valid virtual path.");
 617
 618                         bool pathRelative = VirtualPathUtility.IsAppRelative (filePath);
 619                         bool pathAbsolute = pathRelative ? false : VirtualPathUtility.IsAbsolute (filePath);
 620                         HttpRequest req = Request;
 621
 622                         if (pathRelative || pathAbsolute) {
 623                                 bool needSubstring = false;
 624
 625                                 if (pathRelative && filePath.Length > 1)
 626                                         needSubstring = true;
 627
 628                                 string bvd = req.BaseVirtualDir;
 629                                 if (bvd.Length > 1)
 630                                         bvd += "/";
 631
 632                                 string canonizedFilePath = VirtualPathUtility.Canonize (filePath);
 633                                 filePath = VirtualPathUtility.Combine (bvd, needSubstring ? canonizedFilePath.Substring (2) : canonizedFilePath);
 634                         } else
 635                                 filePath = VirtualPathUtility.Combine (VirtualPathUtility.GetDirectory (req.FilePath), filePath);
 636
 637                         if (!StrUtils.StartsWith (filePath, HttpRuntime.AppDomainAppVirtualPath))
 638                                 throw new HttpException (404, "The virtual path '" + HttpUtility.HtmlEncode (filePath) + "' maps to another application.", filePath);
 639
 640                         req.SetCurrentExePath (filePath);
 641                         req.SetFilePath (filePath);
 642
 643                         if (setClientFilePath)
 644                                 req.ClientFilePath = filePath;
 645
 646                         // A null pathInfo or queryString is ignored and previous values remain untouched
 647                         if (pathInfo != null)
 648                                 req.SetPathInfo (pathInfo);
 649
 650                         if (queryString != null)
 651                                 req.QueryStringRaw = queryString;
 652                 }
 653
 654 #region internals
 655
 656                 internal void SetSession (HttpSessionState state)
 657                 {
 658                         session_state = state;
 659                 }
 660
 661                 // URL of a page used for error redirection.
 662                 internal string ErrorPage {
 663                         get {
 664                                 return error_page;
 665                         }
 666
 667                         set {
 668                                 error_page = value;
 669                         }
 670                 }
 671
 672                 internal TimeSpan ConfigTimeout {
 673                         get {
 674                                 if (config_timeout == null) {
 675                                         HttpRuntimeSection section = (HttpRuntimeSection)WebConfigurationManager.GetSection ("system.web/httpRuntime");
 676                                         config_timeout = section.ExecutionTimeout;
 677                                 }
 678
 679                                 return (TimeSpan) config_timeout;
 680                         }
 681
 682                         set {
 683                                 config_timeout = value;
 684 #if !TARGET_J2EE
 685                                 if (timer != null) {
 686                                         TimeSpan remaining = value - (DateTime.UtcNow - time_stamp);
 687                                         long remaining_ms = Math.Max ((long)remaining.TotalMilliseconds, 0);
 688
 689                                         // See http://msdn2.microsoft.com/en-us/library/7hs7492w.aspx
 690                                         if (remaining_ms > 4294967294)
 691                                                 remaining_ms = 4294967294;
 692
 693                                         timer.Change (remaining_ms, (long)Timeout.Infinite);
 694                                 }
 695 #endif
 696                         }
 697                 }
 698
 699 #if !TARGET_J2EE
 700                 void TimeoutReached(object state) {
 701                         HttpRuntime.QueuePendingRequest (false);
 702                         if (Interlocked.CompareExchange (ref timeout_possible, 0, 0) == 0) {
 703                                 timer.Change(2000, 0);
 704                                 return;
 705                         }
 706                         StopTimeoutTimer();
 707
 708                         thread.Abort (new StepTimeout ());
 709                 }
 710
 711                 internal void StartTimeoutTimer() {
 712                         thread = Thread.CurrentThread;
 713                         timer = new Timer (TimeoutReached, null, (int)ConfigTimeout.TotalMilliseconds, Timeout.Infinite);
 714                 }
 715
 716                 internal void StopTimeoutTimer() {
 717                         if(timer != null) {
 718                                 timer.Dispose ();
 719                                 timer = null;
 720                         }
 721                 }
 722
 723                 internal bool TimeoutPossible {
 724                         get { return (Interlocked.CompareExchange (ref timeout_possible, 1, 1) == 1); }
 725                 }
 726
 727                 internal void BeginTimeoutPossible ()
 728                 {
 729                         timeout_possible = 1;
 730                 }
 731
 732                 internal void EndTimeoutPossible ()
 733                 {
 734                         Interlocked.CompareExchange (ref timeout_possible, 0, 1);
 735                 }
 736 #endif
 737 #endregion
 738         }
 739
 740         class StepTimeout
 741         {
 742         }
 743 }